KR19980058782A - Tracking balance control device and method of optical disc player - Google Patents

Abstract

The present invention relates to a tracking balance control apparatus and method for an optical disc player.

To this end, the present invention compares the tracking balance error output from the low pass filter unit 33 to the conventional tracking balance control device with a predetermined reference level signal from the comparator 35 to determine whether or not the tracking balance has been adjusted. If the tracking balance adjustment fails, the control signal for tracking balance control is again provided to the respective members so that the tracking balance control is executed again, and the control for displaying the completion or failure of the tracking balance adjustment is determined. And a display unit 210 that displays that the tracking balance adjustment is made or failed according to the control signal of the microcomputer 200 and the microcomputer 200 generating the signal.

Therefore, the present invention can determine whether or not tracking balance control has been made or failed in controlling the tracking balance in the optical disc player, and when the tracking balance control fails, the tracking balance control can be executed again, and the success of the tracking balance adjustment or This has the effect of displaying the failure.

Description

Tracking balance control device and method of optical disc player

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tracking servo device for an optical disc player, and more particularly, to a tracking balance control device for an optical disc player that appropriately controls a tracking balance error caused by a lens error or the like during production.

Typical optical disc players include compact disk players (CDPs), laser disk players (LDPs), compact disk graphic players (CDGPs), and video compact disk players (VCDPs). video compact disk players) have been developed and used, and recently, digital video disks (DVDs) using MPEG-2 moving picture compression technology have been developed. It is possible to record and play back gigabytes (GB) of data, including data, and to continue to improve its performance.

On the other hand, such optical disc players reproduce images and / or audio recorded on the optical disc and output them through a screen and / or a speaker, and have a higher signal-to-noise ratio than conventional image and / or audio reproducing apparatus, resulting in better image quality. And / or can reproduce signals with sound quality, generate no noise due to irregular reproduction and modulation, very little distortion, no ghosts, and random access. There is a trend that is spreading.

On the other hand, in such an optical disc player, optical is used to read data recorded on the disc. In order to accurately read the data recorded on the optical disc, reproduction must be performed while accurately following a track of a pitch formed on the optical disc. .

In other words, during playback, tracking control must be made to accurately follow the track of the optical disk on which the light rotates. If such tracking control is not performed smoothly, light reading data may be lost to other tracks due to impact or disturbance during playback, and sound may be cut off or the screen may be blurred.

Among such optical disc players, a compact disc (CD) player and a video compact disc (VCD) player will be described as an example.

CD players and VCD players are 1.61 formed by recording data on CDs and VCDs. A tracking servo is adopted to accurately track tracks of m pitches, and is ± 701 as the amount that must be corrected by the tracking servo in CD and VCD players. m is determined in consideration of the eccentricity that occurs when the disc is manufactured and when the disc is mounted in the player. And, in case of tracking servo, this ± 701 eccentricity of m ± 0.11 It should be suppressed to m.

On the other hand, there are two types of tracking servos, tracking balance control and tracking gain control. Among them, tracking balance control detects tracking errors caused by lens errors in the manufacturing process. To control.

1 is a schematic block diagram of a conventional tracking balance control apparatus.

As shown in FIG. 1, the conventional tracking balance control apparatus includes a microcomputer 5 that generates a control signal for tracking balance adjustment, and picks up light reflected from the disk surface by performing optical pickup from the disk. detecting light quantity of the light reflected by each side beam among the light consisting of the main beam and side beams formed on both sides of the main beam, and converting the light quantity signal into an electrical signal (E, F) The first automatic gain control (AGC) amplifier unit 15 which amplifies the output signal of the optical pickup unit 10, the optical pickup unit 10 with the automatic gain-adjusted amplification, and the output signal of the optical pickup unit 10 A second automatic gain control (AGC) amplifier unit 20 for amplifying with automatic gain-adjusted amplification, and a subtraction circuit unit 25 for obtaining a difference signal between signals provided from the first and second AGC amplifier units 15 and 20. And a predetermined predetermined output signal of the subtraction circuit section 25 A first amplifier 30 to amplify with an amplification degree, a low pass filter unit 33 which detects a DC component in an output signal of the first amplifier 30 and outputs it as a DC signal of a predetermined level or higher, and a low pass filter unit 33 Comparator 35 which compares an output signal with a predetermined reference level signal and outputs a difference signal, and a memory that reads and outputs digital data for tracking balance error compensation corresponding to the output signal of comparator 35. 40 and the digital / analog for controlling the amplification degree of the second AGC amplifier 20 by converting the digital data provided from the memory 40 into an analog signal and providing the same to the second AGC amplifier 20. digital / analog: D / A) converter 45 and configured.

As shown in Fig. 1, in the conventional tracking balance control apparatus, the first and second AGCs 15 and 20, the subtraction circuit section 25, the first amplifier 30, the comparator 35, and the memory 40 The D / A converter 45 is designed as a servo IC 100 on the same integrated circuit (IC) substrate at the time of manufacture.

In addition, in FIG. 1, the phase compensator 50, the second amplifier 55, and the pickup driver 110 are components for controlling the tracking gain error, among which the phase compensator 50 and the second amplifier 55 are included. ) Is designed in the same servo IC 100 circuit as the tracking balance controller described above.

That is, the tracking balance control device and the tracking gain control device are not independently configured, but are ultimately all for the tracking servo, and thus are configured in association with each other in the same IC chip as shown in FIG.

On the other hand, in the conventional tracking balance control apparatus as described above, if the tracking balance control command is provided from the microcomputer 5, the tracking balance adjustment, that is, the tracking balance adjustment is completed because the tracking balance adjustment is completed after self-adjusting in the IC 100. It was difficult to judge whether the balance control was actually made or failed, and it was difficult to control the microcomputer 5 to perform readjustment when the adjustment failed.

Accordingly, the present invention has been proposed to solve such a problem in the related art, and an object of the present invention is to determine whether tracking balance control has been performed or failed in performing tracking balance control in an optical disc player. An object of the present invention is to provide a tracking balance control method for an optical disc player that enables tracking balance control to be executed again.

According to a preferred embodiment of the present invention for achieving this object, each of the light consisting of side beams formed on both sides of the main beam after picking up the light reflected from the disk surface by performing optical pickup from the disk An optical pickup which detects the amount of light reflected by the side beam of the light beam, converts the light quantity signal into an electrical signal (E, F), and outputs the signal; A first automatic gain control (AGC) amplifier for amplifying a gain-controlled amplification degree) and a second automatic gain adjustment for amplifying a signal picked up by the other side beam of the output signal of the optical pickup part with an automatic gain-adjusted amplification degree; (AGC) pre-concatenation of an amplifier unit, a subtraction circuit unit for obtaining a difference signal between signals provided from the first and second AGC amplifier units, and an output signal of the subtraction circuit unit A first reference amplifier for amplifying a predetermined predetermined amplification, a low pass filter unit for detecting a DC component in an output signal of the first amplifier and outputting the signal as a DC signal of a predetermined level or more, and a predetermined reference level for the output signal of the low pass filter unit A comparator for comparing the signal and outputting the difference signal, a memory for reading and outputting digital data for tracking balance error compensation corresponding to the output signal of the comparator, and digital data provided from the memory as an analog signal. Optical for adjusting tracking balance error in an optical disc player comprising a digital / analog (D / A) converter for converting and providing the second AGC amplifier part to adjust the amplification degree of the second AGC amp part. In the tracking balance control device of a disc player, the low pass filter unit The tracking balance error is compared with the predetermined reference level signal in the comparator to determine whether tracking balance adjustment has been performed or failed. When the tracking balance adjustment has failed, the control signal for tracking balance control is again provided. The microcomputer generates a control signal for displaying the tracking balance adjustment completion or failure by providing the constituent members to be executed again, and the tracking balance adjustment is performed according to the control signal of the microcomputer. Characterized in that it further comprises a display unit for displaying that.

According to another preferred embodiment of the present invention for achieving the above object, in a method for controlling a tracking balance error occurring in an optical disc player, (a) when the tracking balance control is executed, a control signal for tracking balance adjustment is provided. And a tracking balance error signal generated after the preset time elapses, and determining a tracking balance OK or failure by comparing the tracking balance error signal generated after the preset time elapses. If it fails, the method returns to step (a) to re-execute the tracking balance and, if the tracking balance is OK, to complete the tracking balance adjustment.

1 is a diagram showing a tracking balance control apparatus of a conventional optical disc player.

2 is a block diagram showing an apparatus for controlling tracking balance of an optical disc player according to a preferred embodiment of the present invention.

3 is a detailed block diagram of the microcomputer shown in FIG.

4 is a flowchart illustrating a tracking balance control method of an optical disc player according to a preferred embodiment of the present invention.

5 is a timing diagram for explaining the tracking control method shown in FIG.

<Description of the code | symbol about the principal part of drawing>

10: Optical pickup section 15, 20: AGC amplifier section

25,206: Subtraction circuit section 30: Amp

33: low pass filter 35: comparator

40: Memory 45: D / A converter

5,200: Microcom 202,204: A / D converter

208: comparison control unit 210: display

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram of a tracking balance control apparatus of an optical disk player according to a preferred embodiment of the present invention.

Referring to Figure 2 with reference to the preferred embodiment of the present invention in detail as follows.

As shown in FIG. 2, the tracking balance control apparatus of the optical disc player according to the present invention includes an optical pickup unit 10, first and second AGCs 15 and 20, a subtraction circuit unit 25, and a first amplifier. 30, a comparator 35, a memory 40, and a servo IC 100 composed of the D / A converter 45 and a control signal for tracking balance control, and when the tracking balance adjustment is completed, the adjustment is performed. The microcomputer 200 which provides a control signal for re-executing the tracking balance control to the servo IC 100 upon determining whether or not it has been made or failed and generates a control signal for displaying whether the tracking balance adjustment succeeds or fails. And a display unit 210 displaying whether the tracking balance adjustment succeeds or fails according to the control signal of the microcomputer 200.

Looking at the operation of the tracking balance control apparatus according to the present invention configured as described above are as follows.

When the tracking balance adjustment key signal is input by the user through a tracking balance control command, that is, an input means such as a key input unit (not shown), the microcomputer 200 controls the control signal for adjusting the tracking balance to the servo IC 100. And the components of the servo IC 100 operate accordingly to execute tracking balance control.

That is, the optical pickup unit 10 performs optical pickup from the disk to pick up the light reflected from the disk surface, and then, in the light composed of the main beam and side beams formed on both sides of the main beam. The amount of light reflected by each side beam is detected, and the amount of light signal is converted into electrical signals E and F and output to the first and second AGC amplifiers 15 and 20.

The first AGC amplifier 15 amplifies and outputs the signal E, which is picked up by one side beam of the output signal of the optical pickup unit 10, with an automatic gain-adjusted amplification, and outputs the second AGC amplifier. The unit 20 amplifies the signal F, which is picked up to the other side beam from among the output signals of the optical pickup unit 10 and outputs it to the subtraction circuit unit 25 by amplifying with an automatic gain controlled amplification. Accordingly, the subtraction circuit section 25 obtains the difference signal of the signals provided from the first and second AGC amplifier sections 15 and 20 and outputs the difference signal to the first amplifier 30, and the first amplifier 30 includes the subtraction circuit section. The output signal at 25 is amplified to a predetermined predetermined amplification level and provided to the low pass filter 33.

Then, the low pass filter unit 33, in which the resistor R and the capacitor C provided with the voltage of 1/2 Vcc (2.5 V) are connected in parallel, detects a DC component in the output signal of the first amplifier 30. And outputs a tracking balance error signal TB in which the detected DC component is increased by a DC signal of a predetermined level or more, that is, 2.5V or more, to the comparator 35, and the comparator 35 is a low pass filter 33. The direct current signal provided by the reference signal is compared with a predetermined reference level signal, that is, a 2.5 V level signal, and the difference signal is output to the memory 40.

Accordingly, the memory 40 reads the digital data for tracking balance error compensation corresponding to the difference signal provided from the comparator 40 and provides the digital data to the D / A converter 45, and the D / A converter 45 The amplification degree of the second AGC amplifier part 20 is adjusted by converting the digital data provided from the memory 40 into an analog signal and providing it to the second AGC amplifier part 20.

On the other hand, the microcomputer 200 compares the output signal of the low pass filter unit 33 with a half Vcc, that is, a 2.5V signal when a time required for the operation as described above, for example, 400 ms has elapsed. After the difference signal is obtained, it is determined whether the tracking balance adjustment succeeds or fails by comparing whether the difference signal falls within a preset signal range.

That is, FIG. 3 is a detailed block diagram of the microcomputer 200. As shown in FIG. 3, the microcomputer 200 according to the present invention includes a first analog / digital (A / D) converter 202 and a second. A / D converter 204, subtraction circuit section 206, and comparison control section 208.

The first A / D converter 202 converts the analog tracking balance error signal TB provided from the low pass filter unit 33 into a digital signal and provides it to the subtraction circuit unit 206, and the second A / D converter. 204 converts a 1/2 Vcc signal, that is, a 2.5V signal, into a digital signal and provides it to the subtraction circuit section 206.

Then, the subtraction circuit unit 206 detects a difference signal between the output signals of the first and second A / D converters 202 and 204 and outputs the difference signal to the comparison control unit 208. In addition, the comparison controller 208 compares the difference signal provided from the subtraction circuit unit 206 with a preset signal range, and determines whether the difference signal is included in the preset signal range. If it is determined that the tracking balance adjustment is successful, otherwise it is determined that it has failed. In addition, when it is determined whether the tracking balance adjustment succeeds or fails, the comparison control unit 208 first generates a control signal to the display unit 210 so that the display unit 210 displays the success or failure of the tracking balance adjustment. At the same time, when the tracking balance adjustment has failed, the control signal is generated again by the servo IC 100 so that the tracking balance adjustment is executed again.

4 is a detailed flowchart of a tracking balance control method according to another exemplary embodiment of the present invention, and FIG. 5 is a timing diagram for explaining the tracking balance control method shown in FIG. 4.

When tracking balance adjustment is started in step S10, in step S20, the microcomputer 200 generates a control signal for tracking balance adjustment to the servo IC 100.

Then, in step S30, the microcomputer 200 waits for a predetermined time, for example, 400 ms in the present invention, in which the tracking balance adjustment is performed in the servo IC 100.

Looking at the operation of the servo IC 100 during the above-described waiting time, i.e., during step S30, as shown in FIG. 5, the comparator 35 has three times of each time interval, i.e., t1 to t6 interval. Determine high or low at point 4. In addition, the memory 40 forcibly outputs '0000' data representing a maximum value, for example, a 10 dB value in a first section, that is, a t1 section, and outputs a '1000' representing a 6 dB level in a t2 section. In the t3 section, '1100', which is a little smaller than 4dB, is output. In addition, '1010' and '1001' values, which are smaller and smaller, are output for the t4 and t5 sections.

Thereafter, in step S40, the memory 40 outputs '1000' to set this value as the tracking balance adjustment value, and sets a tracking balance error signal for a target value having a predetermined tolerance, i. Compare with the signal range.

Then, in step S50, the microcomputer 200 compares whether the tracking balance error signal is included in the target value range to determine the tracking balance adjustment ok (K), that is, the success or the engine (N.G), that is, the failure.

If the tracking balance adjustment is successful in step S50, the process proceeds to step S60 to complete the tracking balance adjustment. If it is determined that the tracking balance has failed, the process proceeds to step S20 to retry the tracking balance adjustment.

As described above, the present invention can determine whether or not the tracking balance control has been made or failed in controlling the tracking balance in the optical disc player, and when the tracking balance control fails, the tracking balance control can be executed again, as well as the tracking balance. This has the effect of displaying the success or failure of the adjustment.

Claims (2)

After the optical pickup is performed from the disk to pick up the light reflected from the surface of the disk, the amount of light reflected by each side beam of the side beams formed on both sides of the main beam is detected and the light quantity signal is detected. An optical pickup unit 10 for converting and outputting the electrical signals E and F and a first signal for amplifying the signal picked up by one side beam of the output signal of the optical pickup unit 10 with an automatic gain-adjusted amplification degree; Automatic gain control (AGC) amplifier unit 15 and the second automatic gain control (AGC) to amplify the signal picked up by the other side beam of the output signal of the optical pickup unit 10 with an automatic gain adjusted amplification Predetermined predetermined output signal of the subtraction circuit section 25 and the subtraction circuit section 25 for obtaining a difference signal between the amplifier section 20 and the signals provided from the first and second AGC amplifier sections 15 and 20 The first amplifier 30 to amplify with amplification of And a low pass filter 33 for detecting a DC component among the output signals of the first amplifier 30 and outputting a tracking balance error signal as a DC signal of a predetermined level or more, and outputting the output signal of the low pass filter 33. A comparator 35 for comparing the predetermined reference level signal and outputting a difference signal, a memory 40 for reading and outputting digital data for tracking balance error compensation corresponding to the output signal of the comparator 35; Digital / analog (digital /) for controlling the amplification degree of the second AGC amplifier part 20 by converting the digital data provided from the memory 40 into an analog signal and providing it to the second AGC amplifier part 20. A tracking balance control apparatus for an optical disk player for adjusting a tracking balance error in an optical disk player including an analog: D / A) converter 45, The tracking balance adjustment is failed by comparing the tracking balance error output from the low pass filter unit 33 with the predetermined reference level signal from the comparison unit 35 to determine whether the tracking balance adjustment has been made or failed. If it is, the microcomputer 200 generating a control signal for displaying the tracking balance control completion or failure again by providing a control signal for tracking balance control to the respective members again. and; And a display unit (210) for displaying that the tracking balance adjustment has been made or failed according to the control signal of the microcomputer (200). A method for controlling a tracking balance error occurring in an optical disc player, comprising: (a) generating a control signal for adjusting tracking balance and waiting for a predetermined time when the tracking balance control is executed; (B) The tracking balance error signal generated after the preset time elapses is compared with the preset reference level signal to determine a tracking balance OK or failure, and when the tracking balance fails, the process returns to step (a). And re-running the tracking balance and, if the tracking balance is OK, completing the tracking balance adjustment.